Chair base



FIG. 1 is a perspective view of a chair base incorporating the design of the present invention;

FIG. 2 is a top plan view of the chair base;

FIG. 3 is a side elevational view of the chair base positioned such that the center of the view is between two legs of the base;

FIG. 4 is a side elevational view of the chair base positioned such that one of the legs of the base is in the center of the view;

FIG. 5 is a bottom plan view of the chair base;

FIG. 6 is an enlarged cross-sectional view of one of the legs in FIG. 2 taken along the lines 6--6 near the center of the chair base, shown for purposes of bringing out the transitional design elements of the legs of the chair base as the leg design changes from the hub to the outer leg end;

FIG. 7 is an enlarged cross-sectional view of one of the legs in FIG. 2 taken along the lines 7--7 at the midpoint of the leg, shown for purposes of bringing out the transitional design elements of the legs of the chair base as the leg design changes from the hub to the outer leg end; and,

FIG. 8 is an enlarged cross-sectional view of one of the legs in FIG. 2 taken along the lines 8--8 near the end of the leg, shown for purposes of bringing out the transitional design elements of the legs of the chair base. 

The ornamental design for a chair base, as shown and described. 